This invention relates generally to methods and apparatus for use in so-called barge supporting floater-type vessels and the like, such as floating docks or canal sluices, for preventing ice floes or other foreign objects from entering into the docking basin and, more particularly, to such methods and apparatus wherein nozzle apparatus are utilized to create a flow field in the region of the docking basin inlet which prevents the ice floes or other foreign objects from entering into the docking basin.
A serious problem which typically arises during the docking and undocking of barges in floater-type vessels is that foreign objects, such as ice floes, tend to drift into the docking basin during entry and exit of the barge through the inlet. Such foreign objects can cause severe damage especially in situations where the same become interposed between the bottom of the vessel which is being docked and the docking deck of the floater vessel or when such foreign objects become lodged between docking supports.
Attempts have been made to overcome this problem. More particularly, experiments have been conducted wherein the inlet to the docking basin is provided with mechanical obstructions to prevent the entry of foreign objects into the docking basin during the docking of a barge or the like. However, such mechanical obstructions tend to be expensive and easily damaged during operation.
Additionally, experiments have been conducted wherein floating objects such as ice floes are prevented from entering into the docking basin by means of water currents directed outwardly from the docking basin. However, model tests have shown that the provision of such water currents does not provide an effective solution to the problem. For example, a barge having a flat bow when moving into the docking basin through an ice floe field will tend to push ice floes located in its path into the basin. Similarly, a barge having a flat stern will tend to draw such foreign objects into the docking basin behind it.
Regarding the state of the art, reference is made to applicants' Finnish publication print No. 66511 in which an arrangement is disclosed whereby a barge carrier is provided with pump apparatus by means of which water is removed from the docking basin during the docking of a barge so that an outward flow which would substantially obstruct the entry of the barge into the docking space will not be created and wherein during the exit of the barge from the docking space, water is pumped into the docking space, preferably through screens or the like, so that flow into the docking basin through the loading door is prevented. However, this arrangement does not solve the problems described above in a satisfactory manner.